Favourite backers had victory snatched away when Alabama Lass crashed through a running rail with 100 metres to go.

The mare reacted when jockey Sam Collett gave her a tap with the whip in the Group Three Haunui Farm King’s Plate at Ellerslie Racecourse in New Zealand.

Alabama Lass flashed her tail, ducked sharply to her right and attempted to jump off the course, giving her rider no chance of staying aboard. The incident, on a dramatic Champions Day card, left the Roger James and Robert Wellwood-trained Sweynesday to profit.

James said his thoughts were with Ken and Bev Kelso, who should have gained another first with quirky and talented Alabama Lass, who has earned $1,010,729 in her career to date.

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“It’s not the way you want to win a race as I was standing next to one of the owners of Alabama Lass, who I know very well, while I used to show jump many years ago with Ken and Bev,” James said via Racing News.

“I feel for them but we will take it (the win).

“He is a very good horse and wasn’t that well weighted today as he was giving weight to Alabama Lass, while he also started from the outside barrier."

Sweynesday's partner Masa Hashizum agreed that Alabama Lass would have finished first, adding: "We were travelling well outside the favourite, and he was coming after her, but he had the luck today.”

Alabama Lass and Collett were reported to be unscathed in the drama, on a day when the winners of the $4 million NZB Kiwi (Well Written) and the $1.25m New Zealand Derby (Road To Paris) survived protests to hold onto victory.

"Probably with the weight (58kg) and being in front for so long, she wandered a bit, but she got the job done still," Well Written's jockey Matt Cartwright said after an enquiry looked into the close finish between his mount and Belle Cheval.

“She is a very good horse and you didn’t see her best today."